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CT and MR appearance of subureteric Teflon and periureteral teflon migration: A case report
Magnefic Resonance Imoging, Vol. 10, pp. 487-490, Printed in the USA. Al1 rights reserved.
??Case
1992 Copyright 0
0730-725x/92 $5.00 + .oo 1992 Pergamon Pres Ltd.
Report CT AND MR APPEARANCE OF SUBURETERIC TEFLON AND PERIURETERAL TEFLON MIGRATION: A CASE REPORT
RICHARD J. MELI AND PABLO R. Ros Department of Radiology, University of Florida College of Medicine, Gainesville, FL 32610-0374,USA We present the computed tomography (CT) and magnetic resonance (MR) findings of a case in which an adult patient underwent subureteric injection of polytetrafluoroethylene (PTFE; Teflon@) (STING) to correct vesicoureteral reflux. We report the appearance of periureteral PTFE migration mimicking cystic pathology. Keywordr: Teflon@; Polytetrafluoroethylene netic resonance imaging.
(PTFE); Ureter; Vesicoureteral reflux; Computed tomography;
INTRODUCTION
Mag-
vesicoureteral reflux and is most commonly used in the pediatrie population. Only one report has described the typical magnetic resonance (MR) appearance. 1 We present the computed tomography (CT) and MR
Subureteric injection of polytetrafluoroethylene (PTFE; Teflon@) (STING) was designed to correct
Fig. 1. CT depiction of the typical location of STING, which causes high attenuation
RECEIVED7/26/91; ACCEPTED 10/25/91. Address correspondence and reprint requests to Pablo R. Ros, MD, Department of Radiology, Box 5-374, JHMHC,
in each subureteric region (arrows).
University of Florida College of Medicine, Gainesville, FL 32610-0374, USA. 487
488
Magnetic Resonance Imaging 0 Volume 10, Number 3, 1992
findings of a case in which ureteral PTFE migration created an atypical appearance following STING in an adult patient. The MR characteristics of PTFE help differentiate PTFE migration from pathologie lesions of the pelvis.
maturia exacerbated by activity. Cystoscopy and biopsy demonstrated PTFE granulomas. CT revealed hydronephrosis and scarring of the right kidney, and dilatation of both left and right ureters. CT demonstrated irregular areas of high attenuation in the region of each vesicoureteral junction, consistent with the patient’s previous injection of PTFE (Fig. 1). The distal left ureter was surrounded by a rim of high attenuation, suggesting cephalad migration of PTFE from the original left-sided site of injection at the more caudad vesicoureteral junction (Fig. 2A).
CASE REPORT
A 59-year-old man with a history of chronic reflux underwent two subureteric injections of PTFE 3 and 4 yr ago. For the past 2 yr he has had intermittent he-
(Bl Fig. 2. (A) At the region of the distal left ureter PTFE produces a rim of high attenuation,
creating a CT appearance of a cystic mass with a calcified wal1 (arrow). This appearance represents migration of PTFE from the subureteric injection site. (B) Axial TI-weighted sequence (TR 300 msec, TE 20 msec) does not reveal the left ureteral rim of PTFE. (Figure continued on facing page.)
CT and MR appearance
of
Teflon 0 R.J. MELI
AND
P.R. Ros
489
Fig. 2 continued. (C) On axial T&weightedsequence (TR 2700 msec; TE 80 msec) PTFE appears as a rim of hypointensity relative to the urine that it surrounds (arrows). Urine within the left ureter is of higher signal intensity than urine within the right ureter because of differente in degree of chronic obstruction.
MR imaging was subsequently performed for further evaluation of the CT findings (GE Signa 1.5 T). On axial Ti-weighted (TlW) images (TR 300 msec, TE 20 msec), it was difficult to discern a rim of PTFE surrounding the left ureter (Fig. 2B). However, on axial T2-weighted (T2W) images (TR 2700 msec; TE 80 msec) a rim of low signal intensity surrounding urine of higher signal intensity was readily apparent (Fig. 2C). In addition, on T2W images, urine within the left ureter appeared higher in signal intensity than urine within the right ureter, perhaps due to a differente between the two ureters in degree of obstruction leading to flow differences within the ureters. Corona1 TlW images (TR 600 msec, TE 20 msec) demonstrated an area in the region of the anterior wal1 of the distal left ureter with a higher signal intensity than urine within the more proximal portion of the left ureter and the corresponding area of the right ureter (Fig. 3). DISCUSSION
STING is used for cystoscopic correction of vesicoureteral reflux. The procedure involves injecting 0.2 to 0.8 ml of PTFE paste into the submucosa of the intravesicular portion of the affected ureter.2 The PTFE particles cause a subsequent foreign body giant cel1 granulomatous reaction, which becomes surrounded by fibrous tissue. The PTFE granuloma prevents reflux by anchoring the submucosal ureter to the bladder.3-5 Failure to correct reflux may result from an
insufficient amount of PTFE, perforation of bladder or ureteral mucosa, injection at a wrong site, or periureteral migration of PTFE along tissue planes following injection.6 On CT, PTFE typically appears as a dense mass.’ Our patient manifested the expected dense mass in the region of each vesicoureteral junction. Proximal to this area the density in the region of the wal1 of the left ureter most likely represented migration of PTFE from the original injection site. Kirsch et al. ’ report the MR appearance of PTFE as isointense with the surrounding bladder wall, uterus, and adnexa on TlW images and hypointense relative to the surrounding tissue on T2W images. On T2W images we were able to distinguish the hypointense PTFE from the adjacent hyperintense urine. However, while we were unable to discern PTFE from urine and surrounding tissue on axial Tl W images, we were able to differentiate PTFE from urine on both sagittal and corona1 Tl W images, in which the PTFE demonstrated a slightly higher signal intensity than urine. This differente in signal intensity may be due to PTFE itself, the granulomatous reaction elicited by PTFE, or both. The CT and MR findings in our patient were consistent with the findings described in previous reports. ‘,’ Our patient also demonstrated an apparent migration of PTFE from an original injection site, producing a rim of PTFE surrounding the distal left ureter. This migration created the appearance of a cys-
Magnetic Resonance Imaging 0 Volume 10, Number 3, 1992
(4
(Bl
Fig. 3. (A) Sagittal and (B) corona1 TI-weighted sequence (:TR 600 ms; TE 20 ms) reveal Teflon as hyperintense relative to urine (arrows).
tic mass with a thick calcified wal1 on CT, which, with-
out knowledge of the patient’s history of STING, could have been interpreted as an iliac artery aneurism with peripheral calcification, a cyst arising from a seminal vesicle, cystic degeneration of a pelvic tumor, cystic teratoma, or schistosomiasis. We believe the MR characteristics of PTFE wil1 be helpful to the radiologist in differentiating PTFE from pathologie pelvic lesions in a patient who has undergone STING. REFERENCES 1. Kirsch, M.D.; Donaldson, J.S.; Kaplan, W.E. MR appearance of subureteric injection of Teflon to correct vesicoureteralreflux. J. Comput. Assist. Tomogr. 14:673-674; 1990. 2. O’Donnell, B.; Puri, P. Technical refinements in endoscopic correction of vesicoureteral reflux. J. Urol. 140: 1101-1102; 1988.
Puri, P.; O’Donnell, B. Correction of experimentally produced vesico-ureteric reflux in the piglet by intravesical injection of Teflon. Br. Med. J. 289:5-7; 1984. Blake, N.S.; O’Connell, E. Endoscopic correction of vesico-ureteric reflm by subureteric Teflon injection: Follow-up ultrasound and voiding cystography. Br. J. Radio]. 62:443-446; 1989. Marcellin, L.; Geiss, S.; Laustriat, S.; Becmeur, F.; Bientz, J.; Sauvage, P. Ureteral lesions due to endoscopic treatment of vesicoureteral reflux by injection of Teflon: Pathological study. Eur. Urol. 17:325-327; 1990. 6. Mann, C.; Jequier, S.; Patriquin, H.; LaBerge, 1.; Homsy, Y. Intramural Teflon injection of the ureter for treatment of vesicoureteral reflux: Sonographic appearante. AJR 151:543-545; 1988. 7. Gore, M.D.; Fernbach, S.K.; Donaldson, J.S.; Shkolnik, A.; Zaontz, M.R.; Kaplan, W.E. Radiographic evaluation of subureteric injection of Teflon to correct vesicoureteral reflux. AJR 1.52:115-119; 1989.
??Case
1992 Copyright 0
0730-725x/92 $5.00 + .oo 1992 Pergamon Pres Ltd.
Report CT AND MR APPEARANCE OF SUBURETERIC TEFLON AND PERIURETERAL TEFLON MIGRATION: A CASE REPORT
RICHARD J. MELI AND PABLO R. Ros Department of Radiology, University of Florida College of Medicine, Gainesville, FL 32610-0374,USA We present the computed tomography (CT) and magnetic resonance (MR) findings of a case in which an adult patient underwent subureteric injection of polytetrafluoroethylene (PTFE; Teflon@) (STING) to correct vesicoureteral reflux. We report the appearance of periureteral PTFE migration mimicking cystic pathology. Keywordr: Teflon@; Polytetrafluoroethylene netic resonance imaging.
(PTFE); Ureter; Vesicoureteral reflux; Computed tomography;
INTRODUCTION
Mag-
vesicoureteral reflux and is most commonly used in the pediatrie population. Only one report has described the typical magnetic resonance (MR) appearance. 1 We present the computed tomography (CT) and MR
Subureteric injection of polytetrafluoroethylene (PTFE; Teflon@) (STING) was designed to correct
Fig. 1. CT depiction of the typical location of STING, which causes high attenuation
RECEIVED7/26/91; ACCEPTED 10/25/91. Address correspondence and reprint requests to Pablo R. Ros, MD, Department of Radiology, Box 5-374, JHMHC,
in each subureteric region (arrows).
University of Florida College of Medicine, Gainesville, FL 32610-0374, USA. 487
488
Magnetic Resonance Imaging 0 Volume 10, Number 3, 1992
findings of a case in which ureteral PTFE migration created an atypical appearance following STING in an adult patient. The MR characteristics of PTFE help differentiate PTFE migration from pathologie lesions of the pelvis.
maturia exacerbated by activity. Cystoscopy and biopsy demonstrated PTFE granulomas. CT revealed hydronephrosis and scarring of the right kidney, and dilatation of both left and right ureters. CT demonstrated irregular areas of high attenuation in the region of each vesicoureteral junction, consistent with the patient’s previous injection of PTFE (Fig. 1). The distal left ureter was surrounded by a rim of high attenuation, suggesting cephalad migration of PTFE from the original left-sided site of injection at the more caudad vesicoureteral junction (Fig. 2A).
CASE REPORT
A 59-year-old man with a history of chronic reflux underwent two subureteric injections of PTFE 3 and 4 yr ago. For the past 2 yr he has had intermittent he-
(Bl Fig. 2. (A) At the region of the distal left ureter PTFE produces a rim of high attenuation,
creating a CT appearance of a cystic mass with a calcified wal1 (arrow). This appearance represents migration of PTFE from the subureteric injection site. (B) Axial TI-weighted sequence (TR 300 msec, TE 20 msec) does not reveal the left ureteral rim of PTFE. (Figure continued on facing page.)
CT and MR appearance
of
Teflon 0 R.J. MELI
AND
P.R. Ros
489
Fig. 2 continued. (C) On axial T&weightedsequence (TR 2700 msec; TE 80 msec) PTFE appears as a rim of hypointensity relative to the urine that it surrounds (arrows). Urine within the left ureter is of higher signal intensity than urine within the right ureter because of differente in degree of chronic obstruction.
MR imaging was subsequently performed for further evaluation of the CT findings (GE Signa 1.5 T). On axial Ti-weighted (TlW) images (TR 300 msec, TE 20 msec), it was difficult to discern a rim of PTFE surrounding the left ureter (Fig. 2B). However, on axial T2-weighted (T2W) images (TR 2700 msec; TE 80 msec) a rim of low signal intensity surrounding urine of higher signal intensity was readily apparent (Fig. 2C). In addition, on T2W images, urine within the left ureter appeared higher in signal intensity than urine within the right ureter, perhaps due to a differente between the two ureters in degree of obstruction leading to flow differences within the ureters. Corona1 TlW images (TR 600 msec, TE 20 msec) demonstrated an area in the region of the anterior wal1 of the distal left ureter with a higher signal intensity than urine within the more proximal portion of the left ureter and the corresponding area of the right ureter (Fig. 3). DISCUSSION
STING is used for cystoscopic correction of vesicoureteral reflux. The procedure involves injecting 0.2 to 0.8 ml of PTFE paste into the submucosa of the intravesicular portion of the affected ureter.2 The PTFE particles cause a subsequent foreign body giant cel1 granulomatous reaction, which becomes surrounded by fibrous tissue. The PTFE granuloma prevents reflux by anchoring the submucosal ureter to the bladder.3-5 Failure to correct reflux may result from an
insufficient amount of PTFE, perforation of bladder or ureteral mucosa, injection at a wrong site, or periureteral migration of PTFE along tissue planes following injection.6 On CT, PTFE typically appears as a dense mass.’ Our patient manifested the expected dense mass in the region of each vesicoureteral junction. Proximal to this area the density in the region of the wal1 of the left ureter most likely represented migration of PTFE from the original injection site. Kirsch et al. ’ report the MR appearance of PTFE as isointense with the surrounding bladder wall, uterus, and adnexa on TlW images and hypointense relative to the surrounding tissue on T2W images. On T2W images we were able to distinguish the hypointense PTFE from the adjacent hyperintense urine. However, while we were unable to discern PTFE from urine and surrounding tissue on axial Tl W images, we were able to differentiate PTFE from urine on both sagittal and corona1 Tl W images, in which the PTFE demonstrated a slightly higher signal intensity than urine. This differente in signal intensity may be due to PTFE itself, the granulomatous reaction elicited by PTFE, or both. The CT and MR findings in our patient were consistent with the findings described in previous reports. ‘,’ Our patient also demonstrated an apparent migration of PTFE from an original injection site, producing a rim of PTFE surrounding the distal left ureter. This migration created the appearance of a cys-
Magnetic Resonance Imaging 0 Volume 10, Number 3, 1992
(4
(Bl
Fig. 3. (A) Sagittal and (B) corona1 TI-weighted sequence (:TR 600 ms; TE 20 ms) reveal Teflon as hyperintense relative to urine (arrows).
tic mass with a thick calcified wal1 on CT, which, with-
out knowledge of the patient’s history of STING, could have been interpreted as an iliac artery aneurism with peripheral calcification, a cyst arising from a seminal vesicle, cystic degeneration of a pelvic tumor, cystic teratoma, or schistosomiasis. We believe the MR characteristics of PTFE wil1 be helpful to the radiologist in differentiating PTFE from pathologie pelvic lesions in a patient who has undergone STING. REFERENCES 1. Kirsch, M.D.; Donaldson, J.S.; Kaplan, W.E. MR appearance of subureteric injection of Teflon to correct vesicoureteralreflux. J. Comput. Assist. Tomogr. 14:673-674; 1990. 2. O’Donnell, B.; Puri, P. Technical refinements in endoscopic correction of vesicoureteral reflux. J. Urol. 140: 1101-1102; 1988.
Puri, P.; O’Donnell, B. Correction of experimentally produced vesico-ureteric reflux in the piglet by intravesical injection of Teflon. Br. Med. J. 289:5-7; 1984. Blake, N.S.; O’Connell, E. Endoscopic correction of vesico-ureteric reflm by subureteric Teflon injection: Follow-up ultrasound and voiding cystography. Br. J. Radio]. 62:443-446; 1989. Marcellin, L.; Geiss, S.; Laustriat, S.; Becmeur, F.; Bientz, J.; Sauvage, P. Ureteral lesions due to endoscopic treatment of vesicoureteral reflux by injection of Teflon: Pathological study. Eur. Urol. 17:325-327; 1990. 6. Mann, C.; Jequier, S.; Patriquin, H.; LaBerge, 1.; Homsy, Y. Intramural Teflon injection of the ureter for treatment of vesicoureteral reflux: Sonographic appearante. AJR 151:543-545; 1988. 7. Gore, M.D.; Fernbach, S.K.; Donaldson, J.S.; Shkolnik, A.; Zaontz, M.R.; Kaplan, W.E. Radiographic evaluation of subureteric injection of Teflon to correct vesicoureteral reflux. AJR 1.52:115-119; 1989.